Anode adjustment means for mercury cathode electrolytic cells

ABSTRACT

THE INVENTION RELATES TO IMPROVEMENTS IN APPARATUS FOR THE ADJUSTMENT OF THE ELEVATION OF ANODES IN A HORIZONTAL MERCURY CELL EMPLOYING A VERTICAL MOTION COORDINATING MEMBER COMPRISING THE COMBINATION OF A ROTARY MEMBER, A TUBE AND A BAND. ROTATION OF THE VERTICAL MOTION COORDINATING MEMBER ASSURES UNIFORM POSITIVE VERTICAL MOVEMENT OF THE ANODE-SUPPORTING MEMBER.

March 19, 1974 E. N. MACKEN ANODE ADJUSTMENT MEANS FOR MERCURY CATHODE ELECTROLYTIC CELLS Filed Aug. 21, 1972 llllllllllllll N @Nuw w\ W W M ii, g K k m wk W \w W United States Patent 3,798,149 ANODE ADJUSTMENT MEANS FOR MERCURY CATHODE ELECTROLYTIC CELLS Elmer N. Macken, Stamford, Conn., assignor to Olin Corporation Filed Aug. 21, 1972, Ser. No. 282,530 Int. Cl. B2311 1/12; C22d 1/04 US. Cl. 204-225 9 Claims ABSTRACT OF THE DISCLOSURE The invention relates to improvements in apparatus for the adjustment of the elevation of anodes in a horizontal mercury cell employing a vertical motion coordinating member comprising the combination of a rotary member, a tube and a band. Rotation of the vertical motion coordinating member assures uniform positive vertical movement of the anode-supporting member.

This invention relates to cells for the electrolysis of aqueous solutions. More particularly the invention relates to improvements in apparatus for the adjustment of the elevation of anodes in horizontal mercury cells.

Horizontal mercury cells usually consist of a covered, elongated trough sloping slightly towards one end. The cathode is a flowing layer of mercury which is introduced at the higher end of the cell and flows along the bottom of the cell toward the lower end. The anodes are suspended from conductive lead-ins and are spaced a short distance above the flowing mercury cathode.

In cells of this type, the distance between the anodes and the mercury cathode is very important. This anodecathode spacing should be as small as possible to reduce the wasteful consumption of energy, for example, in the production of heat. However, if this distance is too small, secondary reactions take place, particularly the direct attack on sodium amalgam by chlorine bubbles. This distance is ordinarily maintained, if possible in the range of & to inch, preferable about M; to A inch.

To maintain an optimum anode-cathode spacing it is necessary that the anode be adjusted frequently and preferaibly automatically. It is often advantageous to adjust the anode-cathode spacing for a set or group of anodes which are interconnected so that all anodes in the set are uniformly adjusted to the same spacing. It is therefore necessary that all parts of the anode adjusting assembly move the same distance during an adjustment for a specified anode-cathode spacing. Under normal operation the distance which the anode is moved is from about 0.008 to about 0.04 inches. In moving an anode set these small distances there are occasions, particularly when the anode set is being lowered, where all members of the anode adjustment assembly do not move the same specified distance, thereby giving an anode adjustment where some members of the set are not at the desired anode-cathode spacing.

An anode adjustment system as described, for example, in US. 3,390,070, has upright members attached at spaced intervals along the lateral edges of the cell cover. A rotary member is attached to each upright member and is connected by drive means to at least one other rotary member. Anode-supporting members extending across the cell are supported from below by the rotary members attached to the upright members. A set of anodes at spaced intervals are suspended from an anode-supporting member. Motor means connected to the drive means turn the rotary members and these vertically move the anode-supporting members. While the upward movement of the anode-supporting member is forced by the rotary member, downward movement is gravity-dependent.

Using an anode adjustment system of the type described 3,798,149 Patented Mar. 19, 1974 above, anodes of unequal weight distributed across an anode-supporting member can cause a variation in anodecathode spacing among members of an anode set upon lowering the anodes as downward movement is gravitydependent.

In addition, in an anode adjustment system capable of employing various types of anodes, for example, metal or graphite, it is necessary to assure positive downward movement of the anode-supporting member regardless of the weight of the anode used.

It has also been found that flexible rubber seals used to prevent the escape of cell gas from apertures in the cell cover for anode lead-ins but permitting the vertical movement of the lead-ins, tend to harden upon ageing. This hardening tends to restrict movement of the anode lead-ins.

In addition, it has been found that the flexible section of the metal conductor supplying current to the anode bus bars, in the case of corrosion, sulfers reduced flexibility which in turn reduces the mobility of the anode adjustment system where the anode-supporting members are also current-carrying members.

Misalignment of mechanical components including, for example, Washers, insulators, and spacers can also occur where gravity dependent downward movement of the anode adjustment apparatus takes place.

One object of the present invention is to provide improved means for adjusting the anode-cathode spacing in a mercury cathode cell.

Another object is to provide for the uniform vertical movement of an anode-support member while adjusting the anode-cathode spacing of an anode set.

Broadly the invention resides in improvements in mercury cathode electrolytic cells having a bottom, two sides forming a trough, and a cover. Threaded upright members are located at spaced intervals along the lateral edges of the upper side of the cover. Anode-supporting members are arranged transversely of the cell and have threaded upright members passing through openings in the anode-supporting members. Support means are attached to the threaded upright members to provide adjustalble support for the anode-supporting members. Anodes are suspended from the anode-supporting members. A rotary member is attached to each of the upright members with a drive means engaging a plurality of rotary members and motor means connected to said drive means.

In such a mercury cell, the invention comprises the combination therewith of a tube attached to the rotary member, enclosing the threaded upright member and passing thru the opening in the anode-supporting member, a band surrounding the tube and secured by attachment means thereto; where the band has a width greater than that of the opening in the anode-supporting member. The combination of the rotary member, band and tube providing a vertical motion coordinating member for the anode-supporting member during rotation of the rotary member.

FIG. 1 is a sectional view showing an electrolytic mercury cathode cell employing one embodiment of the apparatus of this invention.

FIG. 2 is an enlarged cross section of another embodiment of the apparatus of this invention.

FIG- 1 illustrates mercury cathode cell 1 having a cell bottom 2, sides 3 and cell cover 4. Threaded upright members 5 are threaded into nuts 6 attached to lock Washers 7 welded to cell cover 4. Sprockets 8 are welded to supports 9 and both are internally threaded to match the threads on upright member 5. Sprocket sleeves 10 are attached to the upper part of supports 9 and surround, but are not attached to upright members 5. Sprocket collars 11, positioned above anode-supporting channel 17, are held fast to sleeves 10 by set screws 12. Thrust washers 13 and insulating washers 14 are below collars 11 and above insulating bushings 15 and sprocket spacers 16. Bushings 15 insulate sleeves 10 and upright members from conductive anode-supporting channel 17. Insulating washers 18, thrust washers 19 and washers 20 separate anodesupporting channel 17 from sprocket supports 9 and sprockets 8.

Anode-supporting channel 17 is drilled with holes at spaced intervals to receive anode lead-ins 21. Anode leadins 21 and their protective sleeves 22 pass through apertures in cell cover 4 which are closed by means of a flexible rubber boot 23. Boot 23 prevents the escape of cell gas while allowing vertical movement of lead-ins 21. Anodes 24 are attached to the lower end of lead-ins 21 and are spaced a controlled distance above cell bottom 2. The anode lead-ins 21 are suspended from anode-supporting channel 17 by upper lead-in nuts 25 and lower lead-in nut 26 both threaded on lead-in 21 and together with washers 27 and 28 attach anode lead-ins 21 to anodesupporting channel 17. Flexible conductor 29 supplies electric current to conductive anode-supporting channel 17. Chain 30 engages the teeth of sprockets 8 and is attached to motor means (not shown). Energizing chain 30 turns sprockets 8 which in combination with supports 9, sleeves and collars 11 provides uniform positive vertical movement for conductive anode-supporting channel 17.

FIG. 2 illustrates an enlarged cross section of another embodiment of the apparatus of this invention in which vertical motion coordinating member 40 is an integral unit comprised of the sprocket, support and sprocket sleeve, which together with collar 11 secured to member 40 by set screw 12 provide positive movement to nonconductive anode-supporting member 41 upon rotation of member 40.

The present invention is particularly applicable to the anode adjustment system disclosed in U.S- Pat. 3,390,070, and Japanese Pat. 23,309 (1961). The entire specification of US. 3,390,070, is incorporated by reference herein.

While one embodiment has been described in which the rotary member is positioned below the anode-supporting member, it will be readily recognized by those skilled in the art that the rotary member can be placed above the anode-supporting member with the tube extending downward through the opening in the anode-supporting member and the band secured to the tube at a place below the anode-supporting member.

The threaded upright members are either partially or completely threaded over their entire length. A plurality of upright members are secured to the top of the cell cover, being located along both sides of the cover at spaced intervals. In a preferred embodiment threaded upright members are oppositely paired, that is they are located on opposite sides of the cover, equidistant from the end of the cover with uniformly spaced intervals between each upright member along a side.

Rotary members are suitably wheels, for example, a sprocket, a suitable type of gear or a flat or V-pulley. They are preferably threaded for attachment to the threaded upright members.

Drive means for the rotary members includes endless and flexible types, such as chains or belts or non-flexible types such as gear trains. Where the rotary member is a sprocket, Reynolds or Morse type chain is suitably.

used.

The tube attached to each rotary member on the up-.

The band surrounding the tube is the sprocket retainer and can have any suitable form, e.g., a collar, ring, or bushing- It is attached to the tube by means such as a set screw, pin or key and together with the tube and rotary member moves the anode-supporting member in a vertical direction during the rotation of the rotary'member.

Anode-supporting members have any suitable form including flat plates, T-bars or, advantageously, a channel or angle with the web horizontal and the flange vertical, extending upward or downward form the Web. The anodesupporting members are advantageously arranged transversely of cell and anodes depend therefrom. In a preferred embodiment where the anode-supporting members are also the current-carrying members, insulators are provided between the anode-supporting members and any conductively attached parts, for example, the rotary member tubes or upright members.

Insulators are suitably formed of plastic materials which are non-conductive and preferably which resist frictional wear. Polytetrafiuoroethylene or a compressed, fabric-reinforced phenolformaldehyde resin are examples of suitable insulating materials.

Employment of the apparatus of this invention permits improved adjustment of anodes in a mercury cathode cell by providing uniform positive vertical movement for the anode-supporting member. This enables the anode-cathode spacing in the cell to be maintained at the desired distance, prolonging the life of anodes and reducing the cost of electrical energy per unit of product.

What is claimed is:

1. In a mercury cathode electrolytic cell apparatus having a bottom, two sides forming a trough and a cover:

(a) threaded upright members located at spaced intervals along the lateral edges of said cover;

(b) anode-supporting members positioned transversely of the cell having said threaded upright members, passing through openings in said anode-supporting members and anodes suspended from said anodesupporting members;

(c) a rotary member on each of said threaded upright members wherein said rotary member has a diameter greater than the diameter of said openings;

((1) drive means engaging said rotary members;

(e) motor means connected to said drive means,

the improvement which comprises in combination therewith;

(f) a tube attached to said rotary member enclosing said upright member and passing through said opening in said anode-supporting member;

(g) a band surrounding said tube and secured by attachement means thereto, said band having a width greater than said opening in said anode-supporting member;

(h) the combination of said band, said tube, and said rotary member forming a vertical motion coordinating member for positive vertical movement of said anode-supporting member during rotation of said rotary member.

2. The apparatus of claim 1 in which said rotary member is attached to said threaded upright member below said anode-support member, said tube is attached to the upper part of said rotary member, passing through said opening in said anode-support member, and said band is secured to said tube above said anode-supporting member.

3. The apparatus of claim 1 in which said rotary member is attached to said threaded upright member above said anode-support member, said tube is attached to the lower part of said rotary member, passing through said opening in said anode-support member, and said band is secured to said tube below said anode-support member.

4. The apparatus of claim 1 in which said tube and said rotary member are formed as an integral unit.

5. The apparatus of claim 1 in which said anode-supporting members are current-carrying members and electrical insulators are inserted between said anode-supporting members, said upright members, said tubes and said rotary members.

6. The apparatus of claim 1 in which said rotary member is a sprocket- 7. The apparatus of claim 1 in which said drive means is a chain.

8. The apparatus of claim 1 in which said attachment means for said band to said tube is a set screw.

9. The apparatus of claim 1 in which each of said anode-supporting members is positioned between a pair of said threaded upright members which are located on opposite sides of said cover and equidistant from the end of said cover.

References Cited UNITED STATES PATENTS 3,390,070 6/1968 Cooper et a1 204-225 X 3,689,398 9/1972 Calefii 204-225 X 3,598,714 8/1971 Schoberle 204-225 X JOHN H. MACK, Primary Examiner D. R. VALENTINE, Assistant Examiner U.S. Cl. X.R. 204250 

